Many methods for a reversal of a drive or a power output shaft have been used or tried in the past as evidenced by U.S. Pat. Nos. 2,150,456 and 3,939,732. Sometimes reversal of a drive is not that necessary, such as in a small mini-bike or motorcycle as in U.S. Pat. No. 3,625,079. However, a practical reverse drive for some motor vehicles is a necessity. Electric starter motors have even been used as a method for reverse in order to spare additional complexity and/or cost, especially in small motor vehicles utilizing mechanical torque converters or continuously variable transmissions.
Low cost differential units are available and are simple and well built as evidenced by U.S. Pat. No. 3,406,592. Therefore the present invention is directed towards a very practical and advantageous method for a forward and reverse drive.